Refrigerating system



Dec. 28, 1926. 1,612,759

A. R. EARNSHAW REFRIGERATING SYSTEM Filed August 14, 1922 2 Sheets-Sheet1 FIG'ilIZ I/VITNESSES:

A a BY 3 TAM/Z36.

I q INVENTOR:

A1 'Umr fi .Eaxwhaw,

De c. 28., 1926. 1,612,759

A. R. EARNSHAW REFRIGERATING SYSTEM Filed August 14, 1922 2 Sheets-Sheet2 W1 TNESSES INVENTOR:

@ firth zzrfii Earnshaw,

Patented Dec. 28, 1926.

V UNITED sTATEs PATENT OFFICE.

ARTHUR R. EARNSHAW, OF WYNNEWOOD, PENNSYLVANIA, ASSIGNOR TO EARNSHAW'MANUFACTURING CORPORATION, OF PHILADELPHIA, PENNSYLVANIA, A COR-PORATION OF DELAWARE.

REFRIGERATIN G SYSTEM.

Application filed August 14. 1922.- Serial No. 581,569.

This invention relates to refrigerating apparatus intended particularly,for domestic use, and an object of the invention is to simplifyapparatus of this type by reducing to a minimumthe number of controllingde vices necessary, and to provide a simple and automatic means wherebyoperation of the apparatus may take place without constant attention orthe necessity of frequent adjustment.

Another object of the invention is to provide a refrigerating systemwhich shall operate at all times at the highest point of etiiciency.This is accomplished in the present invention by virtue of theparticular design of the apparatus and the proportion and relation ofthe several parts whereby the entire amount of active refrigerant: inthe system is maintained at all times in the zone of refrigeration.

Another object of the invention is to pro vide a simple and efiicientrefrigerating apparatus, of the character set forth, with an automaticfloat valve which is uninflucnced by pressure variations and designed toprovide a check between the compressor and cooling coil to permit thebuilding of pressure for condensation ofthe gaseous refrigerant; topermit the refrigerant as fast as it is liquefied under pressure toautomatically pass into the cooling coil, and to prevent the entranceinto the latter of any of the gaseous refrigerant.

A still further object of the invention is to provide a novel form ofpressure controlled switch for starting and sto ping the compressormotor forming part of my system, and means to control the temperature ofthe system through pressure variations acting upon the switch actuatingmechanism.

In addition to the foregoing, this invention comprehends improvementsinthe details of construction and arrangement of the correlated parts tobe hereinafter set forth and particularly pointed out in the appendedclaims.

In the accompanying drawings, Fig. I is a view illustratingdiagrammatically the elements of my improved refrigerating apparatus inassembled relation.

Fig. II is a-view in section of the float valve.

Fig. III is a detail view in section of a fragment of a slightlymodified form of float valve.

Fig. IV is a view of the float in top plan and its connection to thevalve;,and

Fig. V is a view in side elevation of my improved pressure controlledswitch.

With reference to the drawings, 10 indicates a compressor and 11 adirectly coupled prime mover such an electric motor, a cooling fanv 12being mounted upon the coupling shaft connecting the elements. Thecompressor 10 and motor 11 are mounted upon a base 13, upon which restsan inverted channel casing 14 enclosing the elements and constituting anair-tunnel through which air is caused to-flow by rotation of the fan 12so as to carry away the heat generated during operation. The condensingcoil indicated at 15 is also enclosed within the casing 14. and isconnected in the usual manner to the fit) discharge port of thecompressor 10 and to to receive :1 'lu 20 )ermittin access to themechanism within the casing 19 for adjustment when occasion requires. Anoutlet port 21 is provided in the casing 1%), and located the latter forcommunication with said ort is a valve casin 22 having a horizontalvalve seat in which a plug 23 is rotatably held. A stem 24 extendslaterally from the plug 23 and supports a float 25. The plug 23 isprovided with a transverse passage 26 which is adapted to register witha passage 27 extending through the valve casing 22.when the float 25 isin an elevated position. In addition thereto a by-pass 2S isprovided inthe bottom wall of the float casing 19. affording communication betweenthe interior of the latter and the discharge port 21 for shunting thevalve 22. A hand operated valve 29 is interposed in said bypass and isnormally adjusted to closed position.

The upper end of an evaporating element or cooling coil 30 is incommunication with the discharge port 21 while the lower end of saidcooling coil extends into a reservoir 31 having a cavity 32 provided inits upper portion in which pans of water may be received when makingice. The evaporating element may be the coil 30, a chamber or anyenclosure adapted to receive the liquor and permit evaporation thereoffor the purpose of effecting refrigeration. The float casing 19, it willbe noted 'is located at the lower end of the cooling coil 30. The returnor gas line indicated at 33 is connected to the upper portion of thereservoir 31 and is extended upward through the top Wall of therefrigerator .17 and then to the intake port of the compressor 10. Theliquor line 16 and the-gas line 33 are preferably brought into closerelation at a point within the cooling compartment 18 of therefrigerator 17 and this may be accomplished in several ways as forinstance by wrapping the liquor line 16 around the gas line 33 in theform of a coil whereby heat interchange may take place between the twolines. If the compressor and condenser are located above the zone ofrefrigeration the coiling of the liquor and gas lines 16, 33 respectively may be avoided, as the drop is then direct.

The gas line 33 is tapped at a point adjacent the compressor 10 toprovide a branch 34 which is extended to an automatic pressurecontrolling device indicated comprehensively at 35 and operativelyassociated 'with a switch for controlling the feeding of the motor 11 sothat the compressor 10 may be started or stopped automatically inaccordance with variations inpressure in the gas line 33, which areconsistent with variations in temperature in the cooling apparatus.

Any suitable type of pressure controlled switch may be employed but Ihave found the form illustrated in the accompanying.

drawings to be efficient and well adapted for the purpose besides havingseveral advantages inherentto itself in the way of regulation. Indetail, and referring more particularly to Fig. V, the switch 35consists of a hollow expansible element 36 having its interiorestablished in communication with the branch 34 by means of a couplingconnection 37. The element 36 is supported at.

one end upon a standard 38 while its opposite end is free to moveaxially by expansion or contraction of said element, the mov ableendbeing provided with a rod 39 which slides freely in a standard '40. Apair of nut and jam nut couplers 41 and 42are threaded upon the rod andlocated at opposit-e sides of the standard 40. A pair of coiled springs43'and 44 are encircled about the rod 39, the former being interposedbeconnected to the end of the rod 39 the latter having a turnbuckle 47interposed between aligned sections of said rod so that the effectivelength of the latter may be varied for the purpose of adjusting thestroke of the rod 39 to the throw of the switch finger 46.

It will be apparent that by adjusting the nut couples 41 and 42 thetension of the springs 43 and 44 may be placed in such relation that theswitch finger 46 may be thrown at any predetermined rise or fall ofpressure in the gas line 33, and that the pressure variation possiblebetween maximum pressure limits of switch throw-off and thrown-on may bealtered to vary the sensitivity of the system to temperature changes.The expansible element. 36 is practically independent of atmosphericpressure by reason of the springs 43, 44,the tension of which primarilycontrol the degree of expansion and contraction of said element 36.

It will be noted .that the float valve 22 constitutes a check in theliquor line 16 permitting the building of pressure in the condenser 15so that the liquefication of the gaseous refrigerant may be aided andensured. The active refrigerant, and by that I mean liquid refrigerant,flows through the liquor line 16 and into the float casing 19. As theHeat rises under the buoyant influence of the liquor, sufficient to openthe valve 22 the refrigerant flows into the cooling coil until bydrainage'of the liquor said float 25 falls below a predetermined pointcausing the valve 22 to again close, thus preventing the passage of anygaseous refrigerant into the cooling coil 30. It will he noted at thispoint that the operation of the float 25 is not affected in any degreeby pressure or pressure variations in the system but its operation isaffected solely by the presence or absence of liquid in the easing 19.

The active refrigerant flows through the cooling coil 30 and accumulatesin the reservoir 31, absorbing heat from surrounding parts or the'air inthe-refrigerator resulting in the corresponding evaporation of theactive refrigerant, the gaseous refrigerant passing through the line 33back to the compressor. The reservoir 31 is initially filled /to a pointslightly below its top wall or below the mouth of the gas line 33 withliquid refrigerant so that said reservoir is never 'quite full even whencontaining all of the active refrigerant in the system. Consequentlythere is no possibility of any of the liquid refrigerant entering thegas line 33.

device 35 in the manner stated.

The formation of a gas lock in the float casing 19 is prevented to agreat extent by the close relation of the liquor and gas lines 16, 33respectively permitting of heat interchange at a point closely adjacentthe float casing 19. However, should a gas lock occur the accumulatedliquid refrigerant and gas causin the lock may be passed into thecooling coi 30 by manually opening the bypass valve 29. If desiredhowever the bypass 28 may be omitted from the valve structure.

Owing to the fact that the float valve forms an absolute control overthe supply of active refrigerant to the coil, it will be seen that thecooling coil 30 and reservoir 31 are continually supplied at all timeswith a maximum amount of active refrigerant and that the remaining partof the circuit with the exception of the liquor line 16 and condenser 15contains gaseous refrigerant only, the gaseous refrigerant fed to thecondensing coil 15 being quickly reduced to liquid state and immediatelysupplied to the float casing 19. The float valve 25 being automatic inits action, the entire apparatus, particularly in view of the automaticpressure control 35 operates continually Without attention and ensures auniform degree of refrigeration which may be predetermined bypreadjustment of the pressure controlling The opening of the valve 22may be made large enough to prevent the possibility of clogging so thatthe feeding through of liquid is graduated by the angle of rise of thefloat 25 and is greater or less as the supply varies. As the operationof the valve 22 is not influenced by pressure variations the float 25and casing 19 may be small and compact. As no evaporation takes place inthe float valve casing 19, there is no chilling of oil that may bepresent and consequently no clogging of the valve 22.

A slightly modified construction of the valve casing 22 is shown in Fig.III, wherein said valve casing is provided with a reduced extension 36which enters an opening in the bottom Wall of the float casing 19 and isformed with a threaded terminal which enters the port 21 so that a nut37 may be applied to said terminal and turned tightly against a washerinterposed between said nut and the wall of the port, a similar washerbeing interposed between the inner wall of the casing 19 and theshoulder formed by the reduction of the terminal 36. This type of valvecasing permits of a more ready assembly of the parts.

Having thus described my invention, I claim:

1. In an automatic refrigerating a-pparatus including a circulatorysystem, a prime mover under automatic governance of a ressure controlledswitch, a compressor, a fan and a condenser all housed as a unit withinan open-ended casing constituting an air tunnel, in combination with anexposed cooling coil, a casing interposed between the condenser andcooling coil, located adjacent the lower end of the latter, incommunication with the upper end of said coil, a reservoir below thecoil in communication with the lower end thereof, and a float valvepivoted in said casing permitting the passage of accumulated liquidrefrigerant into the cooling coil but preventing the passage of gaseousrefrigerant.

2. In an automatic refrigerating apparatus including a circulatorysystem, a prime mover under automatic governance of a pressurecontrolled switch, a compressor, a fan and a condenser all housed as aunit within an open-ended casing constituting an air-tunnel, incombination with an exposed cooling coil, a reservoir fed directly bythe cooling coil of a capacity to contain all of the liquid refrigerantin the system, a pivotally mounted float valve interposed in the liquorline adjacent the reservoir and cooling coil to permit the passage ofaccumulated liquid refrigerant directly into said cooling coil but toprevent the passage of gaseous refrigerant, and a gas return connectionleading from the reservoir to the compressor.

In an automatic refrigerating appa-' ratus including a circulatorysystem, a prime mover under automatic governance of a pressurecontrolled switch, a compressor, a fan and a condenser all housed as aunit within an open-ended casing constituting an airtunnel, a liquorline supplied by the condenser, a casing connected to said liquor lineto receive liquid refrigerant, an exposed cooling coil supplied fromsaid casing, a float valve in said casing permitting the passage ofliquid refrigerant to the cooling coil but preventing the passage ofgaseous refrigerant, a subjacent reservoirsupplied by said coil, and agas return line leading from the reservoir to the compressor, the liquorline being intimately associated with the gas line by coiling thereaboutat a point adjacent the valve casing.'

In testimony whereof, I have hereunto signed my name at Philadelphia,Pennsylvania, this seventh day of August, 1922.

ARTHUR R. EARNSHAW.

